Hydraulics Pump Testing

The most scientific way to determine a pumps performance is to plot the entire pump pressure vs flow rate curve. This can be done by measuring pressure at the outlet of the pump with a digital manometer and using a gate valve immediately after this pressure measurement point.  Then utilizing this gate valve, adjusting the amount of restriction will net different flow rates and coinciding pressures the pump is producing over its curve.  All of this is preferably done at a very precise 12.00V or the tested voltage as needed.  While testing for pressure and flow rates, data was also collected using multi-meters to capture voltage and current in amps for power consumption data.

In this particular test the pump was specified to run at 12.0V and likely where most water cooling users would operate it, so all testing was conducted at 12.00V +- .03V.  I found the pump would start as low as 5.1V and up to 13.0V and operate just fine.  I did not exceed 13.0V for my test, although it would likely go beyond that point.

Equipment:

• Dwyer Digital Manometer 477 Mark V - Accuracy .5% of Full Scale.  Range 0-20.00 PSI range, Resolution .01 PSI
• King Instruments 7520 Series 0-5GPM, 250mm scale - Accuracy 2% of Full Scale.  Range 0-5GPM, Resolution .1 GPM (can be interpolated to .02GPM)
• Water Source - Household water pressure - 50PSI at >5GPM - Because flow rate readings are instantaneous, household tap water and water pressure are a good and powerful source for pressure drop testing.
• Samlex PSA-305 Variable DC Power Supply - Adjusted voltage to be at 12.00V +-.03V.
• Calterm 66430 Multi-meter - Measured Voltage (DC Volts to .01V resolution)
• Cen-Tech Digital Multi-meter - Measure Current (Amps to .01 Amps Resolution)
• Mastech MS8209 Auto Ranging Multi-meter - Used for sound level decibel measurements. (.1db resolution)

And my results are as follows:

The pump performs very well for the amount of power consumption.  It has performance similar to the D-Tek db-1(DD-CPX-1), the Hydor L20, or the Laing D5 at setting 3.  The overall efficiency peaks out at around 1.2 GPM so the pump itself is well tuned for water-cooling and utilizing its peak efficiency in most setups.  In addition to the pumping power, it should be noted how little power consumption there is on this particular pump.  I know several water coolers that utilize a Laing D5 at lower setting intervals like setting 3 for pure silence, this pump would provide a similar performance level in a silent condition and provide a nice large and integrated reservoir.

The XSPC dual bay reservoir pump does particularly well with the low restriction blocks and radiators of XSPC.  A general rule of thumb for flow rates is to maintain a minimum of .9GPM, preferably 1.0GPM or better.  The reason for this is that thermal performance for many blocks is very flat beyond this point, so additional flow rates produce little to no measureable performance gain in temperature.  Because XSPC happens to have some very low restriction blocks and radiators, I thought it would be helpful to estimate the actual flow rates for various setups.    The following are several estimated flow rates based on pumping and pressure drop curves I have tested myself, you can expect the following (keep in mind the 0.9GPM minimum rule of thumb)  I included the XSPC RS120 radiator and XSPC Delta V2 CPU since I had recently tested them.  I also included one and then a second Swiftech MCW-60 just to see how it would do with a potential CPU/GPU and CPU/GPU SLI combo on flow rates.  These are all low restriction blocks and an estimate based on calculated curves, but a good estimate of flow rates you can expect:

As you can see the XSPC dual bay reservoir pump does particularly well with the low restriction blocks and radiators of XSPC.  Even though it's not a pump as powerful as the Laing D5 or DDC 3.2, if you combine the pump with the relatively low restriction components like the XSPC CPU Delta V2 and their RS line of radiators, you can maintain more than adequate flow rates for even multiple block loops and you'll do so at very low heat dump created by the pump.  This particular pump also has the advantage of very low heat dump compared to more powerful pumps.  So in the end if you select a pump with low heat dump and blocks and radiators with low pressure drop, you can create a very well balanced and efficient system.  The key to pumps is to select a pump that has adequate pumping power with minimal heat dump for the selected components.

Reservoir Bleeding Performance and Sound Level

I'm very impressed with the reservoir performance in its ability to remove air bubbles from the system and operate at a large range of depth levels. Most single bay reservoirs have a very small amount of good operational level drop before they start sucking air back into the outlet barb and into the system.  Remember air is an insulator so air bubbles are not good in your coolant, so bleeding the system of air and maintain that is an important performance task.

Here is a short video of the pump running with my decibel meter running alongside.  It's difficult to be empirical with bleeding capabilities and noise, so I'm beginning to do some small video recordings to let my readers make up their own minds on the issue.  I recorded this in the evening when it's the most quiet in my house (kids were off to bed), so I hope I've also captured the pump sound for you to evaluate yourselves.  The pump was extremely quiet in my opinion with low very vibrations as well, so I suspect this pump would fulfill the needs of even the most particular silence enthusiast.  With an average room ambient noise level of 46.7db, after switching the pump on and recording levels about 6" away, the sound level rose to about 49.7 or a 3.0 db total increase.

XSPC added a special partial circle scoop over the inlet of this pump that draws flow from the bottom of the reservoir and prevents air from entering the pump even with lower than full levels, very nice addition!  You could very easily run the reservoir half empty and still run the system fine without introducing air into the system again.  The very large size of the reservoir helps calm waters as they enter and does a excellent job of removing air in a very short period of time. I tested the reservoir and pump at the full range of flow rates and never had any vortex issues, it performed the bleeding duties very very well!  

Conclusion

I'm very impressed with bay reservoir pump for several reasons.  First while it is a smaller pump, it still has plenty of power to run multiple block systems as long as the components are chosen and matched wisely.  But more importantly it can do this with very minimal power consumption and with silence.  In addition the large dual bay reservoir does a great job at bleeding and can operate with a varied level of coolant so the old problems I've seen with my old bay reservoir would not be an issue here.  Also I like the nice large clear front view, it looks nice but it also functions to provide you with a visual on coolant levels and the slight movement in water would indicate all is well with the pump and flow rate is good.  Finally the low power consumption and heat dump is very important particularly for smaller radiator systems where it counts the most.